Decoding PDF content in a Base64 browser

Question

We will convert HTML to PDF in the backend (PHP) using dompdf . The generated output from dompdf is Base64 encoded using

$output = $dompdf->output();
base64_encode($output);

This Base64 encoded content is saved as a file on the server. When we decode this file contents as follows:

cat /tmp/55acbaa9600f4 | base64 -D > test.pdf

we get the correct pdf file.

But when we pass the contents of Base64 to the client as a string value inside the JSON object (the server provides the RESTful API ...):

{
  "file_data": "...the base64 string..."
}

And decode it with atob (), and then create a Blob object to load the file later, the PDF is always "empty" / broken.

$scope.downloadFileData = function(doc) {
  DocumentService.getFileData(doc).then(function(data) {
    var decodedFileData = atob(data.file_data);
    var file = new Blob([decodedFileData], { type: doc.file_type });
    saveAs(file, doc.title + '.' + doc.extension);
  });
};

, , "", , base64 -D.

/ / , . ( ASCII-) .

, , . - ? !

Base64 PDF:

JVBERi0xLjMKMSAwIG9iago8PCAvVHlwZSAvQ2F0YWxvZwovT3V0bGluZXMgMiAwIFIKL1BhZ2VzIDMgMCBSID4 + CmVuZG9iagoyIDAgb2JqCjw8IC9UeXBlIC9PdXRsaW5lcyAvQ291bnQgMCA + PgplbmRvYmoKMyAwIG9iago8PCAvVHlwZSAvUGFnZXMKL0tpZHMgWzYgMCBSCl0KL0NvdW50IDEKL1Jlc291cmNlcyA8PAovUHJvY1NldCA0IDAgUgovRm9udCA8PCAKL0YxIDggMCBSCj4 + CJ4 + Ci9NZWRpYUJveCBbMC4wMDAgMC4wMDAgNjEyLjAwMCA3OTIuMDAwXQogPj4KZW5kb2JqCjQgMCBvYmoKWy9QREYgL1RleHQgXQplbmRvYmoKNSAwIG9iago8PAovQ3JlYXRvciAoRE9NUERGKQovQ3JlYXRpb25EYXRlIChEOjIwMTUwNzIwMTMzMzIzKzAyJzAwJykKL01vZERhdGUgKEQ6MjAxNTA3MjAxMzMzMjMrMDInMDAnKQo + PgplbmRvYmoKNiAwIG9iago8PCAvVHlwZSAvUGFnZQovUGFyZW50IDMgMCBSCi9Db250ZW50cyA3IDAgUgo + PgplbmRvYmoKNyAwIG9iago8PCAvRmlsdGVyIC9GbGF0ZURlY29kZQovTGVuZ3RoIDY2ID4 + CnN0cmVhbQp4nOMy0DMwMFBAJovSuZxCFIxN9AwMzRTMDS31DCxNFUJSFPTdDBWMgKIKIWkKCtEaIanFJZqxCiFeCq4hAO4PD0MKZW5kc3RyZWFtCmVuZG9iago4IDAgb2JqCjw8IC9UeXBlIC9Gb250Ci9TdWJ0eXBlIC9UeXBlMQovTmFtZSAvRjEKL0Jhc2VGb250IC9UaW1lcy1Cb2xkCi9FbmNvZGluZyAvV2luQW5zaUVuY29kaW5nCj4 + CmVuZG9iagp4cmVmCjAgOQowMDAwMDAwMDAwIDY1N TM1IGYgCjAwMDAwMDAwMDggMDAwMDAgbiAKMDAwMDAwMDA3MyAwMDAwMCBuIAowMDAwMDAwMTE5IDAwMDAwIG4gCjAwMDAwMDAyNzMgMDAwMDAgbiAKMDAwMDAwMDMwMiAwMDAwMCBuIAowMDAwMDAwNDE2IDAwMDAwIG4gCjAwMDAwMDA0NzkgMDAwMDAgbiAKMDAwMDAwMDYxNiAwMDAwMCBuIAp0cmFpbGVyCjw8Ci9TaXplIDkKL1Jvb3QgMSAwIFIKL0luZm8gNSAwIFIKPj4Kc3RhcnR4cmVmCjcyNQolJUVPRgo =

atob() , , base64 -D. ?

Answer 1

btoa() atob() : Exa.

var enc = btoa("this is some text");
alert(enc);
alert(atob(enc));

JSON base64 .

/ JSON ( GitHub).

base64 Q & A. .